The suspected Great Mills shooter, a teen, used a handgun. It's tough for adults to buy one in Maryland.

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Austin Wyatt Rollins, the 17-year-old who opened fire on classmates at Great Mills High School in Southern Maryland last week, injuring one and killing another, died from shooting himself in the head, officials investigating the case said Monday. (Kevin Richardson, Baltimore Sun video)

Austin Wyatt Rollins, the 17-year-old who opened fire on classmates at Great Mills High School in Southern Maryland last week, injuring one and killing another, died from shooting himself in the head, officials investigating the case said Monday. (Kevin Richardson, Baltimore Sun video)

CAPTION

Great Mills High School student Desmond Barnes, 14, and a teacher communicate with a 911 operator after a shooting at the school.

Great Mills High School student Desmond Barnes, 14, and a teacher communicate with a 911 operator after a shooting at the school.

The gun used by the suspected teenage shooter at a St. Mary’s County high school is difficult for adults to buy under Maryland’s tough gun laws.

Law enforcement officials said Austin Wyatt Rollins, 17, used a 9mm Glock handgun in an attack Tuesday morning at Great Mills High School that left him dead and two other teenagers injured.

Gun laws passed in the wake of the Sandy Hook shooting in Newtown, Conn., makes it difficult to buy handguns, reforms passed to deter straw purchases. Those same laws also exempt gun ownership from public records requests.

Although the assault weapons ban the General Assembly passed in 2013 gets the most attention, the legislature also passed a handgun licensing law that year that requires fingerprinting, four hours of training, a $50 fee and an extensive background check to get a handgun license.

Once buyers have a license, they’re subject to the state’s other handgun laws, which require a seven-day waiting period and for buyers to be at least 21 years old . Buyers may also only buy one gun per month unless they hold a special collector’s license.

Gun-control advocates at the time praised the handgun licensing provision as the most effective way to curb gun violence because it would deter so-called straw purchases — when people buy handguns on behalf of those barred from owning them. A dozen states have such handgun permit laws.

The law passed in 2013 also exempts all gun ownership records from the state’s Public Information Act laws. Previously, the Maryland State Police would release information about how many and what type of firearms were owned by people involved in crimes. Now they do not.

Law enforcement officials in St. Mary’s County said Tuesday they would run a trace on the gun recovered from Great Mills to determine who owned it. It was not immediately clear whether that information will be released to the public.

Three people were injured in a shooting at Great Mills High School in Southern Maryland on Tuesday morning, according to a county spokesman.